方法：选取7日龄SD大鼠80只随机分为正常对照组、单纯高氧组、雌二醇干预组以及溶媒干预组，单纯高氧组于氧浓度75%的容器内饲养5d，再置正常空气下饲养至17日龄，雌二醇干预组饲养方法同单纯高氧组，在大鼠7～17日龄间每日皮下注射17β-雌二醇(E₂，植物油稀释，配制浓度为2μg/μL)，每只大鼠0.5μL/d，溶媒干预组饲养方法与雌二醇组相同，药物改为相同体积植物油。通过HE染色、视网膜铺片观测血管改变和增生情况，免疫组化及RT-PCR检测VEGF的表达。

结果：雌二醇干预组突破内界膜的内皮细胞较单纯高氧组及溶媒干预组明显减少(P<0.05)； 视网膜铺片可见雌二醇干预组较之单纯高氧组血管网有不同程度的改善，血管结构清晰，形态基本正常； 免疫组织化学染色以及RT-PCR结果显示： VEGF在雌二醇干预组的表达较之单纯高氧组及溶媒干预组降低，但仍高于正常组。

结论：17β-雌二醇可在一定程度上预防ROP新生血管的产生，机制可能与抑制VEGF的表达相关。

METHODS: Eighty 7-day-old SD rats were randomly divided into normol group, high oxygen group, 17β-estradiol treatment group and vegetable oil treatment group. Rats of the high oxygen group were put into the environment exposed to 75% oxygen for 5d and backed to room air for another 5d to establish the oxygen-induced retinopathy model. The treatment group was given 17β-estradiol by injection with the dose of 0.5uL/rat/d(2μg/μL)before exposed to 75% oxygen. The vegetable oil treatment group is similar to 17β-estradiol treatment group but the medicine changed to vegetable oil. Counting the endotheliocyte nuclei of new vessels which extended from retina to vitreous body in the tissue-slice of HE staining, and investigate the change of retinal blood vessels by using methods of retina flat-mount. The expression of VEGF in retina by immunohistochemistry and reverse transcription-polymerase chain reaction(RT-PCR)analysis.

RESULTS: Rats treated with E₂ showed less neovascularization than high oxygen group and oxygen-exposed rats treated with vegetable oil(P<0.05). Adenosine diphosphate-ase(ADP ase)stained retina flat- mount showed that: less free-vascular areas and new blood vessels were seen in the 17β-estradiol treatment group compared with the high oxygen group. The expression of VEGF in 17β-estradiol treatment group lower than high oxygen group and vegetable oil treatment group, but higher than normal group in immunohistochemistry and RT-PCR analysis.

CONCLUSION:17β-estradiol has prevention effects in retinal neovascularization and the mechanism may involve in its interaction with VEGF.